The present invention relates to a small size information recording and reproducing apparatus, and more particularly to a small size information recording and reproducing apparatus which is compact and can be accessed at a high speed.
As office automation equipment such as personal computers and word processors has become popularized, needs for small size information recording and reproducing apparatus has increased, and 3 1/2 inch or 5 1/4 inch hard disk drives have been marketed. In those small size hard disk drives, a surface record density is improved year by year and a record capacity is increased through the improvement of a magnetic head and a magnetic disk, improvement of a modulation system of information to be recorded and reproduced, and improvement of a head positioning mechanism.
Since the small size hard disk drive should be replaceable with a conventional floppy disk drive, the outer dimension thereof is usually designed to be substantially equal to that of the floppy disk drive. For example, the 5 1/4 inch disk drive preferably has an outer dimension of 82.5 mm in height, 146 mm in width and 203 mm in length (full-height) to conform to a space in which two 5 1/4 inch floppy disk drives can be accommodated, or a dimension of 41 mm in height (half-height) which is one half of that of the full height in order to conform to a space in which one floppy disk drive can be accommodated. The full-height drive does not fully meet the requirement of compactness because of its double height but meets the requirement of large storage capacity.
Such a compact hard disk drive is disclosed in U.S. Pat. No. 4,568,988 and Nikkei Electronics, 9/23/85 issue, pages 153 -172.
The prior art compact hard disk drive can increase the storage capacity but it does not pay attention to the reduction of time required to record or reproduce data (access time) due to the physical movement of a magnetic head on a magnetic disk and it is not suitable for use in a system which requires a short access time such as a high class word processor, a printer having an image processor or a CAD.